In a four-level energy pyramid, if the first level contains 5000 calories of energy, the third level will contain approximatelycalories.?

One function of the immune system is to attack the foreign cells to protect the body. in organ translate , the body recongnizes that the new organ is made of foreign cells. wha kind of medicine would you give a patient to increase the chances of transplate success

Which could be a pathway of food through an ecosystem

How and why organisms are hierarchically classifies